1. Field of the Invention
This invention relates to a cassette container for containing therein, for instance, a magnetic tape cassette (sometimes called xe2x80x9cmagnetic tape cartridgexe2x80x9d) comprising a cassette casing and a single reel which is housed in the cassette casing for rotation and around which a magnetic tape is wound.
2. Description of the Related Art
As a backup medium for a computer memory, there have been known a magnetic tape cassette comprising a thin rectangular cassette casing and a single reel which is housed in the cassette casing for rotation and around which a magnetic tape is wound, a magnetic disc cassette comprising a thin rectangular cassette casing and a magnetic disc housed in the cassette casing for rotation, and the like.
Those cassettes are generally contained in a cassette container when they are transported or stored. The cassette container is formed of polypropylene having certain extent of flexibility and comprises a container body open upward and a lid member which is connected to one edge of the container body by way of a thin hinge portion to be rotatable about the hinge portion to open and close the container body. The lid member is provided with side walls which are fitted in or on side walls formed on the container body when the lid member is closed.
The side walls on the container body or the lid member are sometimes formed only halfway of the side edges of the container body or the lid member from which the side walls are erected. When the side walls are formed in such a state, the side walls can be deformed e.g., can be warped, when the container is released from the mold, just after the mold release or when the molded container is stored. When the side walls are deformed, the side walls of the lid member can interfere with the side walls of the container body to prevent closure of the lid member. The side walls are more apt to be deformed when the container is formed of polypropylene and when the side walls are high.
That is, when opposite ends of the side walls are connected to the walls of the container body or the lid member which extend in perpendicular to the side walls, the side walls are less apt to be deformed. However when at least one of the ends of each side wall is free, the side walls are apt to be deformed when the molded containers at an elevated temperature are cooled or during storage of the containers depending upon the environmental conditions.
In view of the foregoing observations and description, the primary object of the present invention is to provide a cassette container which can suppress deformation of the side walls and prevent interference of the side walls of the lid member with the side walls of the container body upon opening and closure of the lid member.
In accordance with the present invention, there is provided a cassette container comprising a container body having side walls and a lid member which is connected to the container body by way of a thin hinge portion to be rotatable about the hinge portion to close and open the container body and is provided with side walls which are fitted in or on the side walls on the container body when the lid member is closed, wherein the improvement comprises that
a pair of guide ribs having inclined surfaces which are adapted to abut against the side walls of the lid member when the lid member is closed and to guide the side walls of the lid member so that the side walls of the lid member are fitted outward of the side walls of the container body.
In the cassette container in accordance with the present invention, deformation of the side walls of the lid member can be suppressed and the lid member can be smoothly opened and closed, and at the same time, the strength to drop impact of the cassette container can be increased by providing, on the side walls of the container body, guide ribs having inclined surfaces which are adapted to abut against the side walls of the lid member when the lid member is closed and to guide the side walls of the lid member so that the side walls on the lid member are fitted in or on the side walls on the container body.